Pmndrs.docs

Introduction

React-three-fiber is a React renderer for three.js.


Build your scene declaratively with re-usable, self-contained components that react to state, are readily interactive and can participate in React's ecosystem.

npm install three @types/three @react-three/fiber

Does it have limitations?

None. Everything that works in Threejs will work here without exception.

Is it slower than plain Threejs?

No. There is no overhead. Components render outside of React. It outperforms Threejs in scale due to Reacts scheduling abilities.

Can it keep up with frequent feature updates to Threejs?

Yes. It merely expresses Threejs in JSX, <mesh /> dynamically turns into new THREE.Mesh(). If a new Threejs version adds, removes or changes features, it will be available to you instantly without depending on updates to this library.

What does it look like?

Let's make a re-usable component that has its own state, reacts to user-input and participates in the render-loop. (live demo).

Two spinning orange cubes that turn purple on mouse over
import { createRoot } from 'react-dom/client'
import React, { useRef, useState } from 'react'
import { Canvas, useFrame } from '@react-three/fiber'

function Box(props) {
  // This reference will give us direct access to the mesh
  const meshRef = useRef()
  // Set up state for the hovered and active state
  const [hovered, setHover] = useState(false)
  const [active, setActive] = useState(false)
  // Subscribe this component to the render-loop, rotate the mesh every frame
  useFrame((state, delta) => (meshRef.current.rotation.x += delta))
  // Return view, these are regular three.js elements expressed in JSX
  return (
    <mesh
      {...props}
      ref={meshRef}
      scale={active ? 1.5 : 1}
      onClick={(event) => setActive(!active)}
      onPointerOver={(event) => setHover(true)}
      onPointerOut={(event) => setHover(false)}>
      <boxGeometry args={[1, 1, 1]} />
      <meshStandardMaterial color={hovered ? 'hotpink' : 'orange'} />
    </mesh>
  )
}

createRoot(document.getElementById('root')).render(
  <Canvas>
    <ambientLight intensity={Math.PI / 2} />
    <spotLight position={[10, 10, 10]} angle={0.15} penumbra={1} decay={0} intensity={Math.PI} />
    <pointLight position={[-10, -10, -10]} decay={0} intensity={Math.PI} />
    <Box position={[-1.2, 0, 0]} />
    <Box position={[1.2, 0, 0]} />
  </Canvas>,
)
Show TypeScript example
npm install @types/three
import * as THREE from 'three'
import { createRoot } from 'react-dom/client'
import React, { useRef, useState } from 'react'
import { Canvas, useFrame, ThreeElements } from '@react-three/fiber'

function Box(props: ThreeElements['mesh']) {
  const meshRef = useRef<THREE.Mesh>(null!)
  const [hovered, setHover] = useState(false)
  const [active, setActive] = useState(false)
  useFrame((state, delta) => (meshRef.current.rotation.x += delta))
  return (
    <mesh
      {...props}
      ref={meshRef}
      scale={active ? 1.5 : 1}
      onClick={(event) => setActive(!active)}
      onPointerOver={(event) => setHover(true)}
      onPointerOut={(event) => setHover(false)}>
      <boxGeometry args={[1, 1, 1]} />
      <meshStandardMaterial color={hovered ? 'hotpink' : 'orange'} />
    </mesh>
  )
}

createRoot(document.getElementById('root')).render(
  <Canvas>
    <ambientLight intensity={Math.PI / 2} />
    <spotLight position={[10, 10, 10]} angle={0.15} penumbra={1} decay={0} intensity={Math.PI} />
    <pointLight position={[-10, -10, -10]} decay={0} intensity={Math.PI} />
    <Box position={[-1.2, 0, 0]} />
    <Box position={[1.2, 0, 0]} />
  </Canvas>,
)

Live demo: https://codesandbox.io/s/icy-tree-brnsm?file=/src/App.tsx

Show React Native example

For installation instructions see react native installation instructions.

import React, { useRef, useState } from 'react'
import { Canvas, useFrame } from '@react-three/fiber/native'

function Box(props) {
  const meshRef = useRef(null)
  const [hovered, setHover] = useState(false)
  const [active, setActive] = useState(false)
  useFrame((state, delta) => (meshRef.current.rotation.x += delta))
  return (
    <mesh
      {...props}
      ref={meshRef}
      scale={active ? 1.5 : 1}
      onClick={(event) => setActive(!active)}
      onPointerOver={(event) => setHover(true)}
      onPointerOut={(event) => setHover(false)}>
      <boxGeometry args={[1, 1, 1]} />
      <meshStandardMaterial color={hovered ? 'hotpink' : 'orange'} />
    </mesh>
  )
}

export default function App() {
  return (
    <Canvas>
      <ambientLight intensity={Math.PI / 2} />
      <spotLight position={[10, 10, 10]} angle={0.15} penumbra={1} decay={0} intensity={Math.PI} />
      <pointLight position={[-10, -10, -10]} decay={0} intensity={Math.PI} />
      <Box position={[-1.2, 0, 0]} />
      <Box position={[1.2, 0, 0]} />
    </Canvas>
  )
}

First steps

You need to be versed in both React and Threejs before rushing into this. If you are unsure about React consult the official React docs, especially the section about hooks. As for Threejs, make sure you at least glance over the following links:

  1. Make sure you have a basic grasp of Threejs. Keep that site open.
  2. When you know what a scene is, a camera, mesh, geometry, material, fork the demo above.
  3. Look up the JSX elements that you see (mesh, ambientLight, etc), all threejs exports are native to three-fiber.
  4. Try changing some values, scroll through our API to see what the various settings and hooks do.

Some helpful material:

Eco system

There is a vibrant and extensive eco system around three-fiber, full of libraries, helpers and abstractions.

How to contribute

If you like this project, please consider helping out. All contributions are welcome as well as donations to Opencollective, or in crypto BTC: 36fuguTPxGCNnYZSRdgdh6Ea94brCAjMbH, ETH: 0x6E3f79Ea1d0dcedeb33D3fC6c34d2B1f156F2682.

Backers

Thank you to all our backers! 🙏

Contributors

This project exists thanks to all the people who contribute.